1. Field of the Invention
This present invention relates to a flat cable.
2. Description of the Prior Art
Currently, there is a variety of signal wires for transmitting signals in the industry. The signal wires are different based on the differences of the transmitted signals. Currently, some of the more commonly seen signal wires are twisted pair cable, coaxial cable, optical fiber cable, flat cable capable of transmitting multi-signals, and so on. Among these, the twisted pair cable is much cheaper, but the frequency of the signal transmission is lower. When the frequency is higher, because there is no shielding between the signal wires, the transmitted signals over contiguous signal wires are heavily interfered, the accuracy of the signal transmission lowers, and the transmission speed is also much constrained. Thus, comparing with the twisted pair cable, the performance of the coaxial cable and the optical fiber cable is better; that is, high frequency signal can be transmitted, and the transmission speed is fast, but the cost is more expensive.
As IT industry develops faster, the data rate is higher and higher, the data volume is bigger and bigger, the frequency is higher and higher, and the request for the transmission carrier is tougher and tougher. A flat cable as the carrier of multi-data transmitted simultaneously satisfies the requirement of high volume of data and high speed of transmission, and to a certain extend, it also solves the interference problem in high frequency transmission, such as cross talk and so on. However, the present flat cable either simply eliminates the cross talk by cross arranging signal terminals and ground terminals or shields the entire signal wires with a shielding layer similar to a coaxial cable. The shielding efficiency of the former is worse, and there is still an interference problem in transmitting high frequency signals. The shielding efficiency of the latter is very good, the division property is also fine, but the cost is too expensive to manufacture in bulk.
Therefore, there is a need to design a new flat cable to solve the defects mentioned above.